Tag: temperature

Climate change is real, and it’s affecting us all. From severe heat waves to extreme flooding, here are 8 negative effects of climate change. You’d wish it was all just a hoax… Number 8: Destruction of archeological sites We often think about how changes in the climate are threatening the lives of humans, animals, and plants on the planet. But we fail to realize that it’s not only the living that are affected by climate change. In fact, archeological sites – priceless windows to our past – are suffering as well. High sea waves are hitting Easter Island, the famous site of the moai – mysterious giant head-and-torso statues built by ancient Polynesians. The platforms supporting the moai are slowly being damaged by sea water, and if this continues, the monolithic figures might fall off and end up at the bottom of the ocean one day. Mesa Verde National Park in Colorado is also at risk, and is cited as one of the places most vulnerable to climate change in the US.

There are thousands of archeological sites here, constructed by the ancient Puebloans thousands of years ago. But rising temperatures have caused frequent wildfires, and with it the destruction of rock carvings. This also causes the exposure of new sites and artifacts that become vulnerable to erosion and flooding. These are just two examples of many priceless ancient artifacts and ancient archeological sites in the world that are at risk. Archeologists seem to be in a race against time to document and protect these places before they are gone forever. Number 7: Food shortages We’ve mentioned how climate change and global warming leads to drought, deforestation, and pest infestation. All of this combined causes one major problem – it inhibits the ability of farmers to grow food. In order to grow, crops need to be on fertile land, which becomes largely unavailable due to water shortages.

Food shortages have not occurred widely yet, and international trade will likely prevent any major famine to affect us soon – at least not in the near future. But at the rate we’re going, food prices will soon skyrocket, both due to shortages and the need for refrigeration when extreme heat waves come hitting. Third World countries on the other hand, have it harder. In less developed countries, drought equates to star facial and suffrage sing. Prolonged drought and conflict have left 16 million people across East Africa on the brink of star facial and in urgent need of food, water and medical treatment. Number 6: Rising CO2 levels Since the Industrial Revolution over 2 centuries ago, we’ve gradually been producing more and more Carbon Dioxide on a regular basis. With large scale industrialization and the burning of fossil fuels, we’ve put a total of 2000 gigatons of CO2 in the atmosphere, and about 40% of it has stayed there.

Humans have only been roaming this planet for a relatively short period, yet today’s CO2 levels are the highest they have ever been for millions of years. C02 is one of the main gases contributing to the greenhouse effect, the process by which radiation from the atmosphere heats the planet’s surface. The greenhouse effect is essential for supporting life on the planet, but its extreme intensification has led to global warming. Number 5: Global Warming Global warming – it is the main form of climate changing, and the 2 terms are even often used interchangeably. As of right now, the Earth is warming at a scary rate, 10 times faster than at the end of the Ice Age. Since we started measuring global surface temperature in 1850, each decade seems to surpass the previous, and that rate does not seem to be slowing down. This directly affects us in a number of ways, mainly in the form of drought and extreme weathers. Since the previous century, mega droughts have been appearing everywhere all over the Earth.

Rainfall has been scarce, farms get deserted, and lakes are drying up. Some lakes have even dried up completely, and are no longer existent. An example is Bolivia’s Lake Poopo, which was once its country’s second largest lake. The process of global warming brought increased temperatures to the region, and its evaporation rate multiplied exponentially since the 1990s. By December 2015, Lake Poopo had completely dried up, leaving only a few marshy areas. According to scientists, it is unlikely that it will ever recover. While some places are affected by drought, other places are more vulnerable to extreme weathers in the form of heat waves and storms. The frequency and duration of heat waves has increased greatly within the past half century, and are only going to get worse. Heat waves alone kill more people in the United States compared to natural disasters like tornadoes, earthquakes, and floods combined. Global warming also affects storm formation, by decreasing the temperature difference between the poles and the equator.

Some experts have found a correlation between global warming and the intensity of recent Atlantic Ocean tropical cyclones such as Katrina, Wilma, and Sandy. Number 4: Losing our forests Climate change affects all life on the planet, and this includes forest ecosystems, many of which have been destroyed indirectly by global warming. Bark beetles are major pests that feed and breed between the bark and wood of various tree species, damaging them in the process. These insects thrive in warm temperatures, and as a consequence of global warming, have expanded their ranges and proliferated widely in the forests of North America and Europe. Millions of acres of forest have been destroyed due to bark beetle infestation in recent years. Another cause of widespread deforestation is wildfire. While climate change does not directly cause trees to burn up, wildfires are generally the result of forests getting extremely dry.

Global warming lessens the humidity of forest areas, making them vulnerable to catch on fire. Forests in the western coast of USA, particularly in California, get set ablaze often during dry seasons. If rain fell more often, these forest fires would be extinguished much quicker. There has indeed been a notable increase in wildfires in California within the last decade compared to the decade before, meaning a correlation with climate change is very much likely, and would probably get worse with rising temperatures. Number 3: Insufficient energy to meet demands Since the dawn of mankind, people have learnt of various ways to keep themselves warm – from starting simple fires to creating electric-powered heaters. One of the main reasons for energy demand used to be heating, as people needed to survive long and chilly winters. But a global trend that started in the past century has seen a reversal, especially with the invention of cooling devices like refrigerators and air conditioners.

With the climate getting warmer and warmer, the demand for cooling has skyrocketed. With the increase in carbon emissions and the resulting hot temperatures, the demand for more energy to produce cooling is getting out of control. The worse thing is that this creates a neverending heat-producing cycle. More demand results in more power plants and cooling devices being created, which when used, emits more carbon that heats up the environment. Our only hope is the creation and use of clean energy sources that could keep up with the demands while breaking this vicious cycle. Research and development in solar power shows promise. On the other hand, hydro-electric power is expected to fall behind, as global warming and droughts have caused a decrease in river water levels. Without enough water flow, generators at the dams will not be able to provide energy.

Meanwhile, sea levels are rising, creating a potential risk of flood and storms that could cripple power generators along coastlines. This would disrupt power transmission to entire cities, and create a more desperate demand for energy. Number 2: Melting ice caps & rising sea levels Water covers more than 70% of our planet, and they absorb most of the heat added to the atmosphere. So it’s only natural that is where the extreme changes of climate change are seen. Sea levels around the world have been rising a 10th of an inch every year, and they’re already up 8 inches since 100 years ago. There are two reasons for this. One water expands as it gets warmer. Two, because glaciers, ice caps and icebergs are melting, so they add up to the ocean’s water volume. White sea ice is essential in reflecting sun rays back up into the atmosphere.

Without an ice layer, the dark ocean absorbs the heat rays, feeding the cycle forward. Summer sea ice in the Arctic has decreased a staggering 40% since just 40 years ago, making it the lowest in 1400 years. Antarctica is also experiencing a similar thing, with its western glaciers melting at an alarming rate. At this current rate, the oceans would be up a meter higher by the end of this century. Coastal settlements would be flooded, and many of them would become uninhabitable. And it’s not just cities, but entire nations are also at risk of being wiped off the map. The island country of Maldives is particularly endangered, and is at risk of being swallowed up by the ocean within the next few decades. Their leaders’ pleas to the world to cut global greenhouse gas emissions have been generally ignored, and they are already looking into purchasing new land from neighboring countries to settle their people in the future. Number 1: Animal extinction All the damages caused by climate change is not only affecting us humans, but nearly all the other species on the planet are also struggling to adapt to these changes that we have caused. A lot of animals, mostly birds, are seen beginning their seasonal migrations a lot earlier.

For instance, scientists have found that the Icelandic black-tailed godwits have started migrating 2 weeks earlier than normal to escape the summer heat. Some animals are moving away from their natural habitats towards cooler areas in higher elevations. The distribution patterns of Adelie penguins across Antarctica have also changed significantly. They are known to mainly feed on Antarctic krills, which are small crustaceans that stay under ice caps. But with fewer ice caps remaining, Adelie penguins find themselves in short of food supply leading to mass migrations. All this migration of various animal species is indeed a sign of the climate getting warmer every year. We have also seen a disturbing change within the behavior of several animals. The melting of polar ice in the summer has led to Polar bears channel arising their own cubs out of desperation in order to stay alive. The ocean is our planet’s largest carbon sink. With more Carbon Dioxide released into the atmosphere, more of it ends up dissolving into the ocean, causing a decrease in the water’s pH levels.

Although still far away from turning the ocean into acid, creatures with calcium shells are really sensitive to these slight changes. The ocean is on the course of hitting a pH level of 7.8 within a century, which would mean the end of about one third of the ocean’s species. The Orange-spotted filefish has already gone locally extinct around Japan due to extensive coral bleaching and hypersensitivity to warm waters. Some animal species have already gone totally extinct. The Golden toad that was once native to the forests of Costa Rica was last sighted in 1989, having likely all bite off due to high temperatures. They were known to mate in wet conditions, and the repeated dry seasons presumably ended their species..

Hayhoe: These days, to get attacked, all we have to do is step foot off campus and tell anybody, even a local Kiwanis club, or a local church, or even a group of elementary school kids, that climate change is real, and then the angry letters start to flood in. Mann: Typically the attacks are not really about the science. The attack on the science is a proxy for what is really an effort to discredit science that may prove inconvenient for certain special interests. Oreskes: That’s when I started getting attacked. And that was when life sort of changed, it was a bit going through the looking glass. I started getting hate e-mail. What happened then was I mentioned to a couple of colleagues what was going on, and one of my colleagues at Scripps, at the Scripps Institution of Oceanography, said to me, “You should talk to Ben Santer.

Something sort of similar happened to him.” Santer: I remember sitting in a bar in Madrid with Stephen Schneider, the late Stephen Schneider, immediately after the final sentence had been agreed on in the 1995 report, a sentence that’s forever engraved on my memory. The balance of evidence suggests a discernible human influence on global climate. Here we are at this bar, and Steve says to me, “This changes everything, you know. Your life is going to be changed forever.” I had no idea what he was talking about. I really didn’t. Hayhoe: There is definitely a pattern of what happens: nasty e-mails, complaints to your university, requests for your e-mails, and a lot of attacks online. Mann: Often it takes the form of an attack on individual scientists. It’s part of the strategy of ad hominem attack.

Santer: Go after the scientist. Go after their integrity. Go after their funding. Make life miserable for them. Mann: I have received letters in the mail that in one case contained a while powder that I had to actually report to the FBI. They had to come to my office and investigate this and send this off to a lab to make sure that it wasn’t anthrax or some very dangerous substance that my entire department would have been subject to because of this. Santer: Then there’s the power of the Internet, which really was not available back in 1995, to harness your supporters to go after individual scientists, send them threatening e-mails or worse, and let them know, “We’re watching you. We don’t like you. We don’t like what you do.

” Mann: One of the tactics that you see in climate change denialism is an effort to spin and misrepresent peer reviewed scientific studies. So often studies that say one thing, for example, show that some aspect of climate change is even worse than we thought, will somehow be spun by climate change deniers as if it doesn’t provide evidence for concern. Oreskes: Clearly misrepresenting scientific information, cherry picking scientific data, one egregious example that we talk about in the book is an early work by Jim Hansen that Bill Nierenberg, Bob Jastrow and Fred Seitz take out of context and use it to argue that climate change is caused by the sun when, in fact, if you go back to the original paper, Hansen is arguing exactly the opposite. Santer: I think an additional weapon in the arsenal is Freedom of Information Act requests, which are being used not really to advance understanding or, again, shed light on complex scientific issues but as a tactic to threaten, to intimidate, to throw a spanner in the works to take up your time.

Mann: They will bully editors to try to get them to retract articles that are a threat to their case, their case being that climate change isn’t real, it’s not something to worry Oreskes: The weirdest day of my whole life practically was the day I got a phone call from a reporter in Tulsa, Oklahoma ,who said to me, “Are you aware of the fact that Senator James Imhofe is attacking you?” [laughter] I was like, at that time, I honestly didn’t know who Senator Imhofe was. In fact, I think I had been to Oklahoma maybe once but, I mean, and so I said, “No, I have no idea.” At first I thought he was making a mistake, this was some other, well, I have a very unusual name, so it didn’t seem plausible it was some other Naomi Oreskes. And then he had, he read to me from this speech that Imhofe was making and it was part of what we all are very familiar with now that I was a part of the “global conspiracy,” the scientific conspiracy to bring down global capitalism. And I remember thinking, “Conspiracy?!? Scientists are not that organised.” Santer: hacking e-mails, releasing them, all of these things. The technology has moved on since 1995, but it’s the same playbook: don’t really focus on the science and advancing understanding, contributing, but tear down, destroy.

Hayhoe: I think the best we can do is shield ourselves from the attacks and try not to dwell on them, unless it’s a safety issue, in which case we should take appropriate steps, and try to move on, focusing on what we want to achieve rather than what’s trying to hold us back. Mann: So if you are a prominent scientist, if you participate in the public discourse, as I’ve often said, you better develop a thick skin because you will be attacked personally. Hayhoe: My number one rule of thumb is: do not Google myself. I don’t want to see. My number two rule of thumb is to not read the comments section. I don’t want to know. Oreskes: One of the things that I think is really important us that by writing about these things and by documenting about it in a scholarly way with high standards of documentation, we can explain to our colleagues, our institutions, editors at journal, and the public and the media what this is. Because this is not a scientific debate.

I mean if I have one message that’s what my message has been all along and it still is: this is not a scientific debate; it’s a political debate. But it’s a political debate being made to look like a scientific debate. We now know why people do that. Because it’s a very very effective strategy because if you can make people think it’s a scientific debate then people will think it’s too soon to act. But if people see the truth, if they realise that this is a political debate, that it’s related to people’s ideologies to their values, structures, that gives a whole different cast. So it’s very very important for people to understand the character of what this thing is. Santer: Some things are worth fighting for. That perhaps was the most profound lesson for me back then: that a clear public understanding of the science, doing the kind of thing that you’re doing here, that was truly worth fighting for..

House: The carbon cycle is, very simply, it’s about the cycling of carbon through natural systems – through plants, through soils, through the ocean – and back out into the atmosphere. Le Quéré: In the natural carbon cycle, there’s a lot of fluxes of carbon dioxide, so the carbon goes in and out of the ocean, in and out of the terrestrial biosphere every year. House: The carbon is constantly flowing between these different systems and large amounts of carbon moves all the time. Le Quéré: I mean in the terrestrial biosphere, in the trees and the forests, it’s very easy to see. If you live in a place that has a forest area with seasons, you see in the winter the trees they have no leaves, and the spring comes and the leaves build up. This is all good carbon dioxide that goes in the leaves. And in the fall and in the autumn when the leaves fall down then their carbon is emitted back in the atmosphere.

So you have a huge signal there of CO2 going in and out of the atmosphere. House: So the ocean will take up the CO2, it dissolves in the surface of the ocean and also when the ocean will release CO2 to the atmosphere and that depends on the concentration of CO2 in the atmosphere and the concentration of CO2 in the ocean. And they form a balance with each other. There’s a continuous massive exchange of carbon dioxide between the atmosphere on land and the atmosphere on the ocean. That is roughly in balance until we introduce human change. Osborn: The experiment that we’re inadvertently perhaps conducting with the climate system is to move huge volumes of carbon from these stores undergrounds in the form of fossil fuels and bringing them to the surface and burning them and adding this carbon to the atmosphere. Le Quéré: What we’re doing now is putting everything out of balance, so we’re adding carbon to the atmosphere. It’s new carbon. It’s not part of the natural cycle.

It’s one that we’ve dug out of the fossil reservoir where they were stored, and we’ve put them back in the atmosphere. This is new carbon, and it puts the system out of balance. House: Although the human emissions are much smaller than the natural fluxes, the natural fluxes approximately are in balance and so they’re not causing an increase of carbon dioxide in the atmosphere. The human emissions, however are very rapid, and the natural systems don’t have time to respond to them. And so you get a net imbalance of raised carbon dioxide concentrations in the atmosphere. Lunt: It’s unequivocal that the amount of carbon dioxide in the atmosphere is increasing and is increasing fast and is increasing faster than ever. House: Oh the rate of change now is incredibly rapid, and what’s more it’s pushed us outside the bounds of what we’ve seen in terms of atmospheric concentration throughout the Ice Ages. Thompson: We have not had levels of C02 at 400 parts per million by volume in 800,000 years of history. House: In the Earth’s past throughout in and out of the Ice Ages, the concentration of CO2 in the atmosphere ranged between about 180 parts per million to 280 parts per mission.

And it took thousands of year for it to change between those states. The difference is now it’s gone up to 350 and even topping 400 parts per million on a single day basis. And that’s happened over a period of a couple hundred years. Friedlingstein: Every single generation is emitting more than the previous generation because emission of CO2 increased exponentially. We emit it so far, if you start from the beginning, which is like the industrial revolution in 1750 or something, when we start to burn fossil fuel, from that time up until today we emitted something like 2000 gigaton of CO2. More than half of this has been emitted over the last 50 years. Thompson: And we know where that CO2 is coming from because we do the isotopes of the carbon. We know it’s coming from fossil fuels. Le Quéré: So carbon is increasing in the atmosphere, but it doesn’t entirely stay there, so about half of the emission and maybe a bit more than half of the emission that we put in the atmosphere ends up in the natural environment. It ends up in the ocean and in the forest. Friedlingstein: For the carbon cycle today absorbed about half of the emissions we put in the atmosphere, so we emit, as I said, 40 gigaton of CO2 per year, about half of it, 20 gigaton of CO2 are taken back from the atmosphere by the land and by the ocean.

House: There’s a multitude of different processes that remove carbon dioxide from the atmosphere. So for example, CO2 from the atmosphere dissolves in the surface of the ocean and then that’s turned over and taken into the deep ocean. Really for that amount of CO2 to be completely removed from the atmosphere it has to be completely dissolved and go down into the deep ocean. And then we’re talking about geological timescales – so hundreds and thousands of years. Le Quéré: So what happens when we put carbon emissions into the atmosphere, new carbon from burning fossil fuel or from different station, what happens is this takes a long time for this carbon to readjust in the land and ocean. Eventually if we’re prepared to wait long enough, so that’s thousands of years, a lot of this carbon, maybe 70 percent will end up in the ocean, and the reason this takes time is that you have different adjustment times, so the CO2 goes in the surface ocean, it takes about 1 year to dissolve. But how it is transported from the ocean’s surface to the intermediate and to the deep ocean depends on the ocean circulation.

The ocean circulation takes hundreds to a thousand years to mix the entire ocean. That’s the timescale that is really relevant here is taking a molecule of CO2, we’ve put it in the atmosphere, how long is it going to take before it ends in the deep ocean? House: So about 65 to 80 percent of the carbon dioxide pulse that’s put into the atmosphere will be removed within about 2 to 200 years. The rest of it, the remaining 35 percent, will take between 2 and 20 millennia to be completely removed from the atmosphere. So roughly you have to think whatever we’re doing today, whatever CO2 is being emitted, roughly a third of it is going to stick around essentially forever really when you consider it in our lifetime. Pelto: We can’t change the atmosphere, the chemistry, with one of the main constituents carbon dioxide by 25 percent and expect nothing to happen. You change your diet by 25 percent. You decide you’re going to start consuming 25 percent more calories, and you don’t change your exercise or anything else. You can’t realistically expect nothing to happen. And that’s what you have to understand.

If we change fundamentally our atmosphere chemistry, we can’t expect climate to stay the same..

You may have heard of global climate change, which is often called "global warming." Whether or not people accept that humans are causing global warming, most folks have an opinion about it. But how much do regular people understand the science of climate change? If you were asked to explain how global warming works, could you? Take a moment to try to explain to yourself how virtually all climate scientists think the Earth is warming. What is the physical or chemical mechanism? Don't feel bad; if you're anything like the people we've surveyed in our studies, you probably struggled to come up with an explanation. In fact, in one study we asked almost 300 adults in the U.S.– and not a single person could accurately explain the mechanism a global warming at a pretty basic level. This is consistent with larger surveys that have shown that people often lack knowledge about climate change.

But how can we make informed decisions without understanding the issues we're debating? Allow us to give you a short explanation of how global warming works: First, here is how Earth's temperature works without considering how humans influence it. The Earth absorbs light from the Sun, which is mostly visible light. To release that light-energy, Earth also emits light. But, because the Earth is cooler than the sun, it emits lower-energy infrared light. So, Earth's surface essentially transforms most to the visible light it gets from the sun into infrared light. Greenhouse gases in the atmosphere, such as methane and carbon dioxide, let visible light passed through, but absorb infrared light–causing the atmosphere to retain heat. This energy can be absorbed and emitted by the atmosphere many times before it eventually returns to outer space. The added time this energy hangs around has helped keep earth warm enough to support life as we know it.

Without this greenhouse effect–caused by these greenhouse gases in the atmosphere– the Earth's average surface temperature would be about 50 degrees Fahrenheit cooler, which is well below the freezing point for ice! So, how have humans change things? Since the dawn of the industrial age, around the year 1750, atmospheric carbon dioxide has increased by 40%– and methane has almost tripled. These increases cause extra infrared light absorption, meaning an extra greenhouse effect, which has caused Earth to heat above its typical temperature range. In other words, energy that gets to Earth has an even harder time leaving it, causing Earth's average temperature to increase– thus producing global climate change. In case you're wondering about what makes greenhouse gases special, here are two sentences of slightly technical information: Greenhouse gases such as carbon dioxide absorb infrared light because their molecules can vibrate to produce asymmetric distributions of electric charge, which match the energy levels of various infrared wavelengths.

In contrast, non-greenhouse gases such as oxygen–that is, 02–don't absorb infrared light, because they have symmetric charge distributions even while vibrating. To wrap, up we'll quickly summarize the mechanism global climate change: Earth transforms sunlight's visible energy into infrared light, and infrared energy leaves Earth slowly because it's absorbed by greenhouse gases. As people produce more greenhouse gases, energy leaves Earth even more slowly– raising Earth's temperature even more than it has already gone up. That's how global warming happens! This wasn't so hard to understand, right? In these few minutes you've hopefully become one of the few people who understand the mechanism of global climate change. Please share this video with others so you can help them understand how global warming works, too.

The Earth’s climate is controlled by the energy balance at the top of the atmosphere. If more heat enters the atmosphere than leaves, then the planet warms. Adding heat trapping gases changes the balance, which in turn causes warming. Ocean heat measurements show that the planet is indeed absorbing heat. Despite this fact, it is often claimed that the global warming has stopped. This claim is inspired by evidence that warming of the atmosphere has been slower over the past one and a half decades. This slowdown is sometimes called the hiatus. However, there are other factors which affect the atmosphere over shorter periods. These can cause faster or slower warming of the atmosphere. To understand the slowdown in warming, we need to understand some of these factors.

If we look at the global surface temperature over the past 3 decades, there are big changes in temperature from year to year. We know the cause of some of these variations. One of the biggest is the El Nino cycle. El Nino is a phenomena in which heat is stored up in the western Pacific Ocean, and then released to the atmosphere in the eastern Pacific. This happens over the course of a few years. El Nino is not predictable, but we can track it in retrospect through sea surface temperature measurements. If we compare past El Nino cycles with temperature changes over the past three decades, we can see that there is a strong relationship between the two. El Nino years tend to be hot years. Recent years have been dominated by the cool phase of the cycle. This is responsible for some of the slowdown in warming. However, El Nino doesn’t explain everything. There are cooler periods in the early eighties and nineties which don’t fit the El Nino cycle.

These were caused by two major volcanic eruptions, El Chichon and Pinatubo. Dust from the volcanoes spread in the upper atmosphere, cooling the surface. Smaller eruptions happen all the time, but can also affect temperatures. There has been an increase in the number of small eruptions over the past few years, offsetting a bit of the greenhouse warming. Another factor is the solar cycle. Satellites tell us that the sun varies in brightness with the sunspot cycle. The last cycle has been particularly weak. A dim sun also offsets a little bit of warming. Yet another factor is pollution. Rapid industrialisation in Asia has led to more particulate pollution in the atmosphere, which also has a cooling effect. The final factor is in the observations themselves. Two of the major temperature data providers, the UK Met Office and NOAA, don’t include the Arctic in their global temperature calculation, because there are no weather stations there.

But the Arctic has been warming faster than anywhere else on the planet. Missing it out leads to an underestimation of the rate of warming. To recap, greenhouse gases have continued to grow over the last one and a half decades. But over the same period, volcanoes, the weak sun and pollution have had a cooling effect, and the rate of warming has been underestimated as well. Two recent studies have put all of these together. If we ignore the short term influences, climate models predict faster warming than we have observed. However, if we use global temperature estimates, and add the influence of El Nino, volcanoes, the weak sun and pollution into the models, then the agreement is good. What can we conclude from this? When we put everything we know into the models, the answers match what we observe. So the slowdown in warming makes sense in retrospect, and doesn’t give us a reason to doubt the models.

However, we couldn’t have predicted it in advance, because we can’t predict volcanoes, pollution or the sun. The slowdown in warming has created a whole family of myths with different levels of sophistication. At one extreme, it is possible to argue that the hiatus should reduce our estimates of climate sensitivity. This is a genuine scientific argument, although the analysis we have just seen suggests that no reduction is required. At the other extreme, it is sometimes claimed that the hiatus disproves the role of CO2 in global warming. They claim that CO2 has increased, but the world hasn’t warmed. This is an example of a strawman, and a complex cause fallacy. Climate science doesn’t claim that CO2 is the only factor which affects temperature. This is why the hiatus is so hard to deal with. The myths may be wrong, but they are simple and convincing. The complex cause fallacy exists because people like things to be simple, but explaining the complex drivers of climate is hard. But in the end, all the hiatus myths revolve around drawing attention away from the big picture. When we look at the big picture, the hiatus does not change our understanding of human caused global warming.

2016 was the globe’s warmest year on record—the third year running that a new record has been set. This was due to the continued influence of global warming and a strong El Niño. While Australia saw its fourth warmest year on record, 2016 will be remembered for a dry start followed by a switch to very wet conditions, as the influence on Australia’s climate shifted from the Pacific, to the Indian Ocean. The 2015–16 El Niño was one of the strongest on record, influencing how the year started in Australia. Northern Australia had its warmest wet season on record. There was below-average rainfall over large areas and a record-low number of tropical cyclones in the Australian region. Ocean temperatures around Australia were warmest on record in 2016. This resulted in severe coral bleaching of the Great Barrier Reef early in the year.

Warm and dry conditions contributed to bushfires: in Victoria near the Great Ocean Road—which burnt from Christmas into the new year; in southwest Western Australia—in early January; and in Tasmania’s northwest—in January and February. Tasmania also saw heavy rainfall and flash flooding in the north and east in late January. This rainfall, brought relief to some of the bushfires, but others continued to burn into late February. Autumn was the warmest on record for Australia, with a severe and prolonged heatwave extending across the north and east in March. In May the El Niño ended, and a negative Indian Ocean Dipole developed with waters warming to the northwest of Australia, becoming a major influence on Australia’s climate for the rest of the year. By July, the negative Indian Ocean Dipole had intensified to one of the strongest on record, and a weak La Niña-like pattern had developed in the Pacific Ocean. This combination of climate drivers saw a switch to much wetter conditions and widespread, drought-breaking rains over much of the country.

It was the wettest May to September on record for Australia. Even northern Australia saw widespread rainfall, during what is usually the dry season, greening regions that had been in drought for several years. The most notable event during this wet period was an East Coast Low in early June, which caused flooding down the east coast of Australia to Tasmania, and damaging coastal erosion in New South Wales. There were also a number of significant storm and wind events which affected the southeast. Winter rain and cloud kept daytime temperatures close to average, but the far north of the country remained exceptionally warm. In the Murray–Darling Basin, already wet soils and full rivers meant rain caused flooding in many areas during September and October. However, the exceptionally wet conditions ended by mid-spring. The monsoon reached northern Australia during the second half of December and a tropical low brought widespread rainfall to the northwest, central Australia and the southeast. Temperatures were cooler than average for many in spring, while December saw a heatwave in the southeast.

So looking back at Australia's climate in 2016. It was a year of extreme weather events, wetter on average overall and our fourth warmest year on record. For the Bureau of Meteorology, I’m Robyn Duell..

The world’s oceans cover more than 70 percent of Earth’s surface. Millions of creatures, great and small, call the oceans home. These massive bodies of water play a crucial role in maintaining the planet’s delicate environmental balance, from supporting a complex food chain, to affecting global weather patterns. But rising air temperatures are warming the oceans and bringing dramatic impacts felt around the globe. Dr. TONY KNAP (Bermuda Institute of Ocean Sciences): One of the things warming does in, say areas off the United States, it creates a much bigger pool of warm water in the surface of the ocean that lends a huge amount of energy to hurricanes and tropical cyclones. THOMPSON: Dr. Tony Knap is the director of the Bermuda Institute of Ocean Sciences, or BIOS. Famous for its luxurious golf courses and pink sand beaches, Bermuda is also home to one of the world’s leading institutes for ocean studies, with a focus on water temperatures.

KNAP: Here off Bermuda, we have probably a better view of it then many other people are going to have over time. THOMPSON: Bermuda is located over 600 miles, or almost 1,000 kilometers, from the coast of North Carolina, in an area of the Atlantic Ocean called the Sargasso Sea. KNAP: We like to think of the Sargasso Sea in the North Atlantic as the canary in the coalmine. It’s the smallest ocean, it’s between North America and Europe and we think if we are going to see changes, we will see them first here in the ocean off Bermuda. THOMPSON: Scientists at BIOS have been measuring the temperature of the ocean since 1954, making it one of the world’s longest ongoing studies of ocean data. KNAP: Well you measure the temperature of the ocean in many ways. In the old days you used to do it with buckets and thermometers. Now you use sophisticated instruments called conductivity, temperature and depth recorders. THOMPSON: These recorders, called CTDs, are large measuring instruments lowered deep into the water at specific locations in the ocean. On this day, Knap and his team are headed to “Station S.

” QUENTIN LEWIS, Jr. (Captain, R/V Atlantic Explorer): The weather is not going to be our friend today, unfortunately. The winds out of the west, it’s 35-40 and some higher gusts. The seas are anywhere from 14 to 16 feet or higher. THOMPSON: Lowered to a depth of three kilometers, or just under two miles, the CTD records temperature, salinity, carbon dioxide levels, and captures water samples. KNAP: This is a screen for the output on the CTD. The temperature will be in red, blue is salinity or the saltiness, and yellow is the oxygen content. THOMPSON: At BIOS, all of the data is then carefully logged and analyzed. Dr. NICK BATES (Bermuda Institute of Ocean Sciences): With this instrument we can see changes that happen over the season, over the year. And then from year to year.

THOMPSON: Using ocean temperature data going back several decades, BIOS research can trace the warming trend. In the past 56 years, it has risen half a degree Celsius. KNAP: Since 1954 we’ve seen, on average, the temperature increasing by a small amount, an equivalent to what is really a half a watt per year which is, doesn’t seem like a lot but over the whole of the ocean, it’s a lot. THOMPSON: What’s a half a watt? KNAP: It’s not much. It’s about a 100th of a degree per year. It’s not a lot. THOMPSON: But that small a difference can make, have a huge impact? KNAP: Yeah. THOMPSON: Really? KNAP: Yeah, because it’s going on every year. You think about how big the ocean is, and how deep it is, and how much energy it has, I mean it’s a tremendous source of heat. THOMPSON: So where is that warming coming from? KNAP: The warming we believe is to due to changes in CO2 in the atmosphere, the atmosphere getting warmer and the surface of the ocean getting warmer.

And that transfer of heat is being made into the ocean. THOMPSON: So what is the impact of a warmer ocean? The rising temperature causes the ocean to expand, and raises sea levels. KNAP: The tides going up by 3.2 millimeters a year. Half of that is attributed to the ocean warming down to 700 meters. The oceans on average 4,000 meters deep so it has a lot more to expand. THOMPSON: Warming temperatures also impact the growth rates of certain organisms at the very bottom of the ocean food chain, like phytoplankton. And so if you see changes in phytoplankton, does that mean that we are going to see changes in the food chain at the ocean? KNAP: If the organisms that eat those organisms, OK, eat the plankton, for example, can’t eat those plankton, then yes you’ll see changes. THOMPSON: And the small changes being recorded could bring even stronger storms.

This report published in 2005 in Science Magazine shows the gradual rise of the number of Category 4 and 5 hurricanes over recent years. An increase in storm intensity like this many scientists believe is the result of the warming of the oceans. KNAP: You think about how big the ocean is, and how deep it is, and how much energy it has. Even if you look at difference in hurricanes intensity, etc., one, one and a half degree centigrade in the water column of one hundred meters makes a massive amount of difference. THOMPSON: Small changes with big consequences for the creatures in the sea and all the people who live along the coasts..